What is the sequence of steps for obtaining a recombinant plasmid?

1. The plasmid is “cut” with restriction enzymes (enzymes that recognize specific nucleotide sequences and break DNA at this point). This sequence is removed, so-called sticky ends are formed on each of the chains.

2. The plasmid is mixed with the required DNA fragment, as well as with the ligase enzyme, which links the cut circular and foreign DNA. Together with the required gene, a marker, for example, an antibiotic resistance gene, is inserted.

3. Mutant cells are planted on a selective medium (for example, containing an antibiotic). Those in which recombination has occurred survive because have a resistance gene. They are used in further work.